1. Field of the Invention
The invention relates to a direction/distance sensing system for a vehicle, and in particular to a stand-alone direction/distance sensing system used to control selected vehicle functions based on the sensed information. More particularly, the invention is directed to an electronic sensor mounted adjacent to the anti-lock braking system tone ring of a vehicle wheel hub, which is capable of determining the direction and distance of travel of the vehicle by sensing the movement of teeth formed on the tone ring, thereby electronically controlling, via a microcontroller which receives the sensed information, one or more selected vehicle functions, including lifting axles, activating safety backup alarms, reinflating suspension air springs, reengaging slider locking pins, disengaging dock ride-height maintenance devices, and the like.
2. Background Art
In recent years, a need has arisen in the heavy-duty vehicle industry due to conveniences desired by users as well as by government-regulated safety requirements. This need is the desire to increasingly automate various functions in heavy-duty vehicles such as semi-trailers and straight trucks. Such automation provides convenience by eliminating the need to manually control selected vehicle functions, and provides a safety feature by ensuring that the function occurs thereby preventing operator error due to forgetting to manually actuate a function that could result in damage to the vehicle or other property, or injury or death to people.
A specific example of one such vehicle function is the control of a self-steering lift axle on the trailer of a semi-trailer, which historically has been accomplished by a pneumatic control device mounted on the trailer. When the vehicle driver wanted to lift or lower the self-steering axle, he/she heretofore has been required to exit the truck cab to manually operate the control. It is desirable to lift a self-steer axle before backing up the vehicle since such self-steer axles only operate properly when the vehicle is moving forward. If the driver forgets to lift the self-steer axle before backing up, tire damage can result.
With the direction/distance sensing vehicle function control system of the present invention, the driver can automatically control the lift axle by moving the semi-trailer a predefined distance in reverse or forward. Specifically, when the semi-trailer moves a short, predefined distance, such as three feet in reverse, the self-steering lift axle is automatically raised by the control system to enable easier maneuvering of the vehicle, such as when the vehicle is being backed up to a loading dock. Conversely, when the semi-trailer moves a longer, predefined distance, such as 80 feet in the forward direction to ensure that it is no longer in a maneuvering mode and is beginning over-the-road travel, the self-steering lift axle is automatically lowered.
The present invention thus eliminates the need for such manually-actuated vehicle function control systems, by mounting an electronic sensor adjacent to the vehicle wheel hub tone ring on one of the non-steer axles, for sensing movement of the tone ring teeth and sending an electronic direction/distance signal to an electronic control unit, which in turn sends an electronic signal to a device which actuates the vehicle function, such as a solenoid for a lift axle.
Objectives of the present invention include providing a discrete system for automatically and simultaneously controlling one or more vehicle functions.
Another objective of the present invention is to provide such a system which is easy to install either as original equipment or as a retrofit on a vehicle, and which is lightweight, cost effective, durable in use, and easy to maintain and replace.
These objectives and advantages are obtained by the present invention characterized as a vehicle having a plurality of rotating wheels, the vehicle including means for sensing a direction of movement of and a distance of travel of a selected one of the plurality of wheels, means for processing the sensed direction and distance information, the processing means being electrically connected to the sensing means, and means for actuating at least one vehicle function, the actuation means being electrically connected to the processing means and being controlled by the processing means for automatically causing the function to occur.